“Temperature is going to significantly affect range. And that remains consistent across the product line,” says John Nielsen, the managing director of engineering and repair at AAA.

The nonprofit motorist organization, which owns and operates 2 fleets of plug-in cars and is in development of a mobile electric vehicle charging system, conducted tests of three different electric cars at three different temperature levels: 95 degrees, 75 degrees and 20 degrees.

Using the city driving test procedure of the EPA-DOE, the test found that the average EV battery range was 105 miles at 75 degrees, but then nosedived to 43 miles at 20 degrees. At 95 degrees, the average EV battery had a range of 69 miles.

Nielsen wouldn’t disclose the 3 models by 3 different automakers, but all three are available nationwide.

The EPA city cycle accounts for coasting and regenerative braking, which feeds power back to the battery. The vehicles were fully charged, then driven on a dynamometer in a controlled climate until the battery was dead.

“What shocked me was the percent reduction in battery range over the 3 cars was the same, which says more about the technology,” Nielsen says, citing the chemistry of lithium ion batteries as the reason for the loss.

“Lithium ion batteries are picky about their temperature,” Nielsen explains, adding that an electric heater is needed to get batteries to the right operational temperature. The heater is a drain on the battery. Additionally, the chemical reaction within the cells is denser in colder temps, which also reduces the range.

This is the same principle outside the car, where cold, dense air increases the drag coefficient. The EPA estimates that internal combustion engines can have a 22 percent drop in fuel economy in 20 degree weather. In hybrid systems its worse, but not as severe as the 57 percent in EVs cited by AAA.

“I was a little bit surprised that the range fell off as large as it did,” says Nielsen, who drives a BMW and just sold his Ford F-250 diesel, which had over 290,000 miles.

AAA has an EV fleet in Manitoba, and the engineers agreed that the rate was consistent with what they’ve witnessed, if not more so.

Another power drain comes from the creature comforts of heating your seats and your windshield, for instance, which weren’t factored into the test cycle.

“The good news is that for the average commuter [16 miles], the EV remains a very good solution in all temperatures,” Nielsen says.